Accommodation stimulation and recording device

ABSTRACT

Embodiments described herein generally relate to devices and methods for stimulation or recording of accommodation of an eye. Accommodation of an eye naturally occurs through contraction of the ciliary muscle. Embodiments described herein can deliver electrostimulation to the ciliary muscle through a pair of electrodes which deliver power over an area of the sclera which is both positioned above and over an area which is substantially equivalent to the surface area of the ciliary muscle. In further embodiments, electrical impulses produced by the ciliary muscle can be received by one or more electrodes positioned proximate the ciliary muscle. Thus, by embodiments described herein, accommodation of the eye can be reproducibly achieved by external stimulation of the ciliary muscle or measured based on electrical impulses generated by or in conjunction with the ciliary muscle.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims benefit of U.S. Provisional Patent ApplicationSer. No. 61/834,921 (UOFH/0009USL), filed Jun. 14, 2013, which is hereinincorporated by reference in its entirety.

BACKGROUND

1. Field

Embodiments disclosed herein generally relate to devices and methods formanipulating and recording accommodation in the eye.

2. Description of the Related Art

Accommodation is the process whereby the young eye changes focus fromdistance to near. This occurs through a contraction of the ciliarymuscle inside the eye. This ciliary muscle contraction causes the lensin the young eye to change shape, which increases the optical power ofthe eye. The normal accommodative response is rapid in the young eye.The young eye can change focus within about 100-200 milliseconds.

Accommodation is progressively lost with increasing age in the conditioncalled presbyopia. Presbyopia is due to a progressive age-relatedincrease in stiffness of the lens. In humans, accommodation can beproduced by having subjects look from a distant target to near-readingtext positioned progressively closer to the eyes (known as visualstimulus elicited accommodation). In visual stimulus elicitedaccommodation, the subject perceives the near object, perceives that thenear object (in this case, text) is out of focus and attempts to makethe near object clear by accommodating. In presbyopes (persons affectedby presbyopia), the subject would perceive the near object is out offocus, but they would not be able to accommodate to change their focusto get the near object in clear focus.

How the eye accommodates, why this physiological function is lost withincreasing age and trying to understand if accommodation can be restoredin presbyopes is an area of significant basic science, clinical andindustry research. Such research is undertaken on human subjects as wellas on animal models including non-human primates, especially rhesusmonkeys. Rhesus monkeys accommodate in a very similar fashion to the wayhumans do. Rhesus monkeys also develop presbyopia.

A significant challenge in this area of clinical and laboratory researchis how to stimulate accommodation either in human subjects or in animalmodels. Stimulating accommodation can be challenging for many reasons.For example, in conscious human subjects although presenting nearreading text may represent a stimulus to accommodate, the subjects maysimply choose not to accommodate or they may not elicit a strong effortto accommodate. Similarly, in animal models, if the animals areanesthetized, it can be challenging to stimulate accommodation.

In both humans and animal models, accommodation can be stimulated byapplying drugs, such as pilocarpine, directly to the eye. This producesan accommodative response because the drugs diffuse into the eye andcause the ciliary muscle in the eye to contract. However, drugstimulated accommodation may be very slow relative to the naturalaccommodative response. In some examples, the drug stimulatedaccommodation can take 30-45 minutes to achieve a maximum. When comparedto the previously described 100-200 milliseconds for naturalaccommodation to occur, known drug induced accommodation techniquesappear inadequate for studying natural accommodation. Further, incurrent drug stimulation models, the accommodation response can only beelicited a single time in each experimental session.

In animal models where a dynamic accommodative response is desired,complex, lengthy and invasive surgical procedures are required tostimulate dynamic accommodative responses with electrical stimulation.As such, the complexity and expense of the procedure, ethical concernsand danger to the animal all act to limit dynamic accommodationexperimentation.

Thus, there is a need for safe and effective exogenous control ofaccommodation in both humans and animal models.

SUMMARY

The embodiments described herein generally relate to methods and devicesfor affecting or recording an accommodation response.

In one embodiment, an electrostimulation device can include a devicebody with a circular shape and an outer circumference, the device bodycomprising an anterior surface and a posterior surface, and on theposterior surface an inner ring electrode and an outer ring electrodeboth comprising an electrically-conductive material, the outer ringelectrode, the inner ring electrode and the outer circumference of thedevice body forming concentric circles and an electrical stimulationsource in electrical connection with the inner ring electrode and theouter ring electrode.

In another embodiment, a scleral contact lens electrode can include adevice body, an inner ring electrode comprising anelectrically-conductive material adapted to contact the posteriorsurface of the scleral contact region, an outer ring electrodecomprising an electrically conductive material adapted to contact theposterior surface of the scleral contact region and circumscribing theinner ring electrode and an electrical stimulation source in electricalconnection with the inner ring electrode and the outer ring electrode.The device body can include a transparent lens with a posterior surfaceand an anterior surface, the posterior surface adapted to contact thecornea and the scleral contact region, the scleral contact regioncircumscribing the transparent lens.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1A depicts a frontal view of an accommodation stimulation speculumaccording to an embodiment;

FIG. 1B depicts a rear view of the accommodation stimulation speculumaccording to an embodiment;

FIG. 1C depicts the accommodation stimulation speculum adapted tocontact an eye according to an embodiment;

FIG. 2 depicts an accommodation stimulation scleral contact lens adaptedto contact an eye according to an embodiment;

FIG. 3 depicts an accommodation stimulation scleral annulus adapted tocontact an eye according to an embodiment;

FIG. 4A depicts a rear view of a vacuum suction accommodationstimulation device according to an embodiment;

FIG. 4B depicts the vacuum suction accommodation stimulation deviceadapted to contact an eye according to an embodiment;

FIG. 5 depicts an accommodation stimulation scleral contact lens adaptedto contact an eye according to an embodiment;

FIGS. 6A-6C are graphical depictions of measurements related toaccommodative responses created by an accommodation stimulation deviceaccording to an embodiment;

FIGS. 7A-7C depict a plurality of stimulated accommodative responsesusing the accommodation stimulation device according to an embodiment;

FIGS. 8A-8D depict a plurality of stimulated accommodative responsesusing an accommodation stimulation device according to an embodiment;

FIGS. 9A-9C depict a plurality of stimulated accommodative responsesusing an accommodation stimulation device according to an embodiment;

FIGS. 10A-10C depict a plurality of stimulated accommodative responsesusing an accommodation stimulation device according to an embodiment;

FIGS. 11A-11C depict a plurality of stimulated accommodative responsesusing an accommodation stimulation device according to an embodiment;

FIGS. 12A-12C depict a single extended stimulated accommodative responseusing an accommodation stimulation device according to an embodiment;

FIGS. 13A and 13B depict an overlay of stimulated accommodationresponses with progressively increasing amplitudes, according to anembodiment;

FIG. 14A is a graph depicting a typical stimulus response relationshipfor increasing stimulus amplitudes according to an embodiment;

FIG. 14B is a graph depicting peak velocity as a function ofaccommodative amplitude according to an embodiment;

FIGS. 15A-15C depict a plurality of stimulated accommodative responseswith progressively decreasing frequencies using an accommodationstimulation device according to an embodiment;

FIG. 15D is a graph depicting the accommodative response amplitudesachieved for stimulus pulse-trains with constant amplitude and variablefrequency according to an embodiment;

FIG. 15E is a graph depicting the accommodative response amplitudesachieved from three sets of measurements for stimulus pulse-trains withconstant amplitude and variable frequency according to an embodiment;

FIG. 16 is a graph depicting a plurality of accommodation responses inan eye using the accommodation stimulation device with a variable pulsewidth for the stimulus pulse-trains of constant amplitude and frequencyaccording to an embodiment;

FIG. 17A is a graph depicting the maximum accommodative response foreach stimulus amplitude for eyes of varying age stimulated by theaccommodation stimulation device according to an embodiment;

FIG. 17B is a graph depicting the maximum accommodative responseamplitude in eight monkeys of differing ages achieved using anaccommodation stimulation device according to an embodiment;

FIG. 18 depicts a method of fabricating an accommodation device,according to an embodiment;

FIG. 19A depicts an accommodation stimulation scleral annulus 1900 cutaccording to an embodiment;

FIG. 19B depicts the accommodation stimulation scleral annulus 1900formed according to an embodiment; and

FIG. 20 depicts the accommodation stimulation scleral annulus 2000including an RF transmitter 2022 according to one embodiment.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements and features of oneembodiment may be beneficially incorporated in other embodiments withoutfurther recitation.

DETAILED DESCRIPTION

Embodiments disclosed herein generally relate to devices that can beplaced on the eye to electrically stimulate accommodation or to recordthe electrical activity of the ciliary muscle when it contracts duringan accommodative effort and methods for exogenous accommodation in humansubjects or in animals, including monkeys.

The accommodation stimulation devices can stimulate accommodationwithout requiring any participation from the subject to elicit anaccommodative response. Accommodation can be achieved through theembodiments described herein in a non-invasive fashion. Theaccommodation stimulation devices described herein can produce a rapidlyoccurring accommodative response, such as in the order of milliseconds,and can elicit many repeated accommodative responses. Further in theaccommodation stimulation devices described herein, the frequency,duration and amplitude of the accommodative responses can be regulatedby controlling the stimulus characteristics. The embodiments disclosedherein are more clearly described with reference to the figures below.

Accommodation Stimulation Speculum

In one embodiment, an accommodation stimulation speculum is provided toachieve accommodation. As used herein, the accommodation stimulationspeculum is a device to hold the eyelids open while deliveringelectrostimulation to the ciliary muscle. The accommodation stimulationspeculum positions a plurality of ring electrodes adapted to contact thesclera over the area of the ciliary muscle. The accommodationstimulation speculum is therefore capable of deliveringelectrostimulation in a non-invasive fashion in either conscious orsedated subjects.

FIGS. 1A-1C depict an accommodation stimulation device according to anembodiment. In this embodiment, the accommodation stimulation device isan accommodation stimulation speculum 100. Generally, the accommodationstimulation speculum 100 has a speculum body 101, with both an anteriorsurface 104 and a posterior surface 120, which is adapted to conform tothe material features of the eye while expanding to hold the eyelids ineither an open or semi-open position. The speculum body 101 can beshaped as two conical frustums which reflect at a convergent plane. Thespeculum body 101 is formed from a non-conductive material. Theposterior surface 120 has one or more electrodes formed thereon. Theposterior surface 120 is positioned inward toward the eye 150 while theanterior surface 104 is positioned opposite the posterior surface 120.The anterior surface 104 can have one or more openings to receiveconnections for the one or more electrodes. Thus, the accommodationstimulation speculum 100 is adapted to deliver electrical stimulationusing the pair of electrodes which are positioned in connection with thenon-conductive posterior surface 120.

FIG. 1A depicts a frontal view of the accommodation stimulation speculum100 according to an embodiment. The accommodation stimulation speculum100 is shown here with a perspective view of the speculum body 101 withan exterior surface 102 and the anterior surface 104. The speculum body101 can be formed of a material which is safe for use in the eye. Thespeculum body 101 is both sterilizable (e.g. non-porous) andnon-conductive. Examples of possible materials include polymers, such assilicones, plastics and elastomers, or combinations thereof. In furtherembodiments, the speculum body 101 can comprise two or more materials,such as an inner portion (core) composed of a first material, such as aceramic, and an outer portion (coating) composed of a plastic with anelastomer.

A first port 112 and a second port 114 are formed in the anteriorsurface 104. The position of the first port 112 and the second port 114can be changed according to the needs of the user. The first port 112can receive a first connection 106 and the second port 114 can receive asecond connection 108. The first connection 106 and the secondconnection 108 can extend out from the anterior surface 104 of thespeculum body 101. The speculum body 101 is formed from a non-conductiveor insulating material whereas the first connection 106 and the secondconnection 108 are made from a conductive material, such as a metal(e.g. copper, silver, platinum, palladium, or aluminum), conductivepolymers or combinations thereof. In another embodiment, the firstconnection 106 and the second connection 108 can be formed of abiocompatible conductive material which is used for fabrication ofmedical electrodes. Biocompatible conductive materials can includesilver, silver chloride, platinum, gold, iridium, stainless steel,tungsten and combinations thereof. Biocompatible materials can furtherinclude printable inks from a biocompatible material such as silver inkor silver chloride ink. The first connection 106 and the secondconnection 108 are electrically connected to an electrical stimulationsource, such as an electrical stimulator (not shown). Commerciallyavailable electrical stimulators which can be used with one embodimentinclude the Accupulser Signal Generator, SYS-A310 or the DigitalStimulator, DS8000, both available from World Precision Instruments,Inc. located in Sarasota, Fla. The electrical stimulator can beregulated such that the amplitude, the pulse width and the pulsefrequency are maintained with specific parameters, described in moredetail with reference to FIG. 1C.

An aperture 110 can be formed in the speculum body 101. The aperture 110is depicted here as a circular opening, however the aperture 110 can beany shape or size which allows access to the eye. The aperture 110 canbe a shape which radiates out from a central point, such as a circle oroval. The edge of the aperture 110 can have a surface texture which isnon-abrasive to avoid damage to the eye.

FIG. 1B depicts a second view of the accommodation stimulation speculum100 according to an embodiment. The speculum body 101 is depicted fromthe perspective of the posterior surface 120. The posterior surface 120is the inner surface of the conical frustum which contacts the eye. Inthis embodiment, the speculum body 101 of the accommodation stimulationspeculum 100 is depicted with the first port 112 and the second port 114extending through the speculum body 101 and connecting the anteriorsurface 104 to the posterior surface 120. The posterior surface 120 canbe coated with a material, such as a soft plastic. The posterior surface120 includes an outer ring electrode 116 and an inner ring electrode118. The outer ring electrode 116 can be concentric to the inner ringelectrode 118.

The outer ring electrode 116 and the inner ring electrode 118 areelectrically connected with the first connection 106 and the secondconnection 108 through the first port 112 and the second port 114.Depicted here, the outer ring electrode 116 is electrically connected tothe first connection 106 through the first port 112 and the inner ringelectrode 118 is electrically connected to the second connection 108through the second port 114. The outer ring electrode 116 and the innerring electrode 118 can each be formed of the same material or adifferent material as the first connection 106 and the second connection108, respectively. Though the inner ring electrode 116 and the outerring electrode 118 are depicted as formed on the posterior surface 120of the speculum body 101, the rings may be formed in or embedded in theposterior surface 120, based on the needs or desires of the user.

FIG. 1C depicts the accommodation stimulation speculum 100 adapted tocontact an eye 150 according to an embodiment. The depiction shows theeye 150 having cornea 156 formed over a lens 158. At the edge of thecornea 156 is sclera 154, which circumscribes the cornea 156. Locatedunder the sclera 154 is ciliary muscle 152. The ciliary muscle 152 isconnected to and manipulates the lens 158 by contraction or extension.Located on top of the sclera 154 and circumscribing the cornea 156 isthe accommodation stimulation speculum 100. The aperture 110 of theaccommodation stimulation speculum 100 forms an inner circumferencecircumscribing the cornea 156. The anterior surface 104 of theaccommodation stimulation speculum 100 further circumscribes the fieldof vision from the eye 150 while the exterior surface 102 forms a ‘V’shape to hold the eyelids open. The posterior surface 120 of theaccommodation stimulation speculum 100 can be adapted to contact thesclera 154 through at least the outer ring electrode 116 and the innerring electrode 118. In one embodiment, the posterior surface 120 of theaccommodation stimulation speculum 100 rests against the sclera 154 ofthe eye 150 with the two concentric electrodes (e.g. the outer ringelectrode 116 and the inner ring electrode 118) resting on and incontact with the sclera 154 above the location of the ciliary muscle152. In one embodiment, the outer ring electrode 116 and the inner ringelectrode 118 are concentric circles which are positioned on a portionof the sclera 154 which corresponds to the inner and outer boundaries ofthe ciliary muscle 152.

As shown, the aperture 110 can be sized to circumscribe the cornea 156of the eye 150. As such, the aperture 110 can be of numerous sizes whichare within the ranges of human and animal eyes. Further embodiments caninclude either increased or decreased size of the aperture 110, suchthat the aperture 110 either covers a portion of the cornea or extendsbeyond the circumference of the cornea.

In operation, power, such as an electrical current, can be deliveredfrom an electrical stimulation source (not shown) at a specific pulsewidth, pulse frequency and amplitude using the first connection 106 andthe second connection 108, described with reference to FIGS. 1A and 1B.This process is referred to herein as electrostimulation. The pulsetrain frequencies can be in the range of from about 10 Hz to about 1000Hz, such as about 200 Hz. The pulse widths can be monophasic or biphasicwith durations from about 100 μs to about 1 ms, such as about 600 μs.

Without intending to be bound by theory, it is believed that the use oftwo concentric ring electrodes provides a more efficientelectrostimulation of the ciliary muscle than multiple independentcontacts. The ciliary muscle connects to and circumscribes the lens. Bycontracting or relaxing, the ciliary muscle changes the focus of thelens in the eye. By delivering the electrostimulation around theentirety of the ciliary muscle, it is believed that the entire ciliarymuscle is activated simultaneously without selective activation oroveractivation at any one point, avoiding strain and providing a bettermodel the native physiology in the eye.

The electrical stimulation is delivered through the first connection 106and through the outer ring electrode 116 to the sclera 154 andsubsequently though the ciliary muscle 152. The power is received by theinner ring electrode 118 and thus by the second connection 108 tocomplete the circuit. When the electrical current is delivered with theappropriate stimulus characteristics, the ciliary muscle 152 isstimulated to contract thus producing an accommodative response. Theciliary muscle 152 contracts based on the characteristics of the powerreceived and accommodates the lens 158 accordingly. The power flowdescribed above can start at either the first connection 106 or thesecond connection 108.

In the above described embodiment, the accommodation stimulationspeculum 100 is positioned under the eyelid with the outer ringelectrode 116 and inner ring electrode 118 positioned over the ciliarymuscle 152 and in contact with the respective portion of the sclera 154.The outer ring electrode 116 and inner ring electrode 118 can deliver anexternal stimulus (e.g. electric current) to the ciliary muscle 152through the sclera 154. By providing an external stimulus to the ciliarymuscle 152 through the sclera 154, accommodation of the lens 158 can beachieved in a quick, painless, non-surgical and non-pharmacologicalfashion. Further, any results can be reproduced with limited expense andcomplexity, allowing further study of the eye.

Accommodation Stimulation Scleral Contact Lens and Scleral Annulus

In another embodiment, the accommodation stimulation device can be anaccommodation stimulation scleral contact lens. The accommodationstimulation scleral contact lens can both provide electrostimulation foraccommodation, such as for presbyopia patients, and provide forcomfortable use by a conscious person, both allowing proper spacingbetween the eye and eyelid and allowing blinking.

FIG. 2 depicts an accommodation stimulation scleral contact lens 200adapted to contact an eye 250 according to an embodiment. Generally, theaccommodation stimulation scleral contact lens 200 includes an externallens region 202 and a scleral contact region 204 and is adapted toconform to the material features of the eye while allowing the eye tofunction normally. The external lens region 202 is a transparentstructure positioned over the cornea 256. The external lens region 202can be either a corrective or a non-corrective lens. Surrounding theexternal lens region 202 is the scleral contact region 204. At least thescleral contact region 204 is formed from a non-conductive material. Thescleral contact region 204 rests on the sclera 254 and includes one ormore electrodes which are positioned or formed on the scleral contactside of the scleral contact region 204. Thus, the accommodationstimulation scleral contact lens 200 is adapted to deliver electricalstimulation using the pair of electrodes which are positioned inconnection with the non-conductive scleral contact region 204.

The accommodation stimulation scleral contact lens 200 can include theexternal lens region 202 which is a convex, transparent structure andthe scleral contact region 204. The external lens region 202 can beformed of a variety of materials including polymers, such as hydrophilicplastics. The external lens region 202 can be less than 12 mm indiameter, such as between approximately 7 mm and 10 mm in diameter.Further, the external lens region 202 can be of a standard thickness forcontact lenses, such as less than 1 mm thick.

Generally, the external lens region 202 and the scleral contact region204 are formed as a single structure, without a defined boundary betweenthe external lens region 202 and the scleral contact region 204. Thescleral contact region 204 should be non-conductive while the externallens region 202 can be either conductive or non-conductive. In someembodiments, the scleral contact region 204 is coated with anon-conductive material. The scleral contact region 204 is about 5 mm toabout 10 mm wide in all directions and circumscribes the external lensregion 202. The accommodation stimulation scleral contact lens 200,including both the external lens region 202 and the scleral contactregion 204, can have a diameter of from approximately 17 mm toapproximately 22 mm. In further embodiments, the scleral contact region204 and the external lens region 202 are separate components which areconnected to form at least a portion of the accommodation stimulationscleral contact lens 200. The scleral contact region 204 and theexternal lens region 202 can be formed separately and connected to oneanother, such as through an adhesive. In embodiments where the scleralcontact region 204 is a separate component, the scleral contact region204 can also be formed of a similar material to the speculum body 100,described with reference to FIG. 1A.

An outer ring electrode 216 and an inner ring electrode 218 can beformed in, on or in connection with the scleral contact region 204. Theouter ring electrode 216 and the inner ring electrode 218 can have thesame attributes and characteristics as described with reference to theouter ring electrode 116 and the inner ring electrode 118 described withreference to FIG. 1A-1C.

The eye 250 is depicted with a cornea 256, a lens 258, a sclera 254 anda ciliary muscle 252, as described above. The ciliary muscle 252 isconnected to and manipulates the lens 258 by contraction or extension.Located over the sclera 254 and the cornea 256 is the accommodationstimulation scleral contact lens 200. In one embodiment, theaccommodation stimulation scleral contact lens 200 is adapted to contactthe eye 250.

The external lens region 202 can be adapted to contact the cornea 256.The external lens region 202 can be a transparent non-correcting lens orit can be a corrective lens, such as a corrective lens for astigmatism,near-sightedness or far-sightedness. The scleral contact region 204 ofthe accommodation stimulation scleral contact lens 200 can be adapted tocontact the sclera 254 through at least the outer ring electrode 216 andthe inner ring electrode 218. In one or more embodiments, the scleralcontact region 204 is on the sclera 254. In one embodiment, theposterior surface 220 of the accommodation stimulation scleral contactlens 200 rests against the sclera 254 of the eye 250 with the twoconcentric electrodes (e.g. the outer ring electrode 216 and the innerring electrode 218) resting on the sclera 254 above the location of theciliary muscle 252.

As described with reference to FIG. 1C, external stimulation at specificfrequencies, pulse widths and amplitudes can be delivered such thatcontraction of the ciliary muscle 252 and subsequent accommodation ofthe lens 258 can be achieved. In this embodiment, the electrostimulationof the ciliary muscle 252 can create accommodation of the lens 258 incombination with correction by using the external lens region 202.

One or more electrical connections (not shown) can be formed in orthrough the scleral contact region 204. The electrical connections forman electrical pathway between the concentric electrodes using theelectrical stimulation source (not shown). The electrical stimulationsource can be either internal or external to the lens. The electricalstimulation source can a battery, a kinetic power source, a solar powersource or others. In one embodiment, electrical connections extendthrough the scleral contact region 204 and are connected to anelectrical stimulation source which is carried on the head of the user.The electrostimulation in this embodiment can be activated based onphysiological detectors, such as by physiological changes associatedwith an attempt at accommodation by the patient, or it can be activatedmanually, such that the patient can self-manipulate the accommodationresponse at the lens 258.

Though described with reference to a single accommodation stimulationdevice (e.g. the accommodation stimulation speculum 100 andaccommodation stimulation scleral contact lens 200), it is understoodthat an accommodation stimulation device can be used on each eye. Infurther embodiments, the accommodation stimulation devices can be usedon each eye where each accommodation stimulation device is connected inparallel to a single electrical stimulation source to achieve binocular(both eyes) accommodation, described hereafter as “daisy chaining” ofthe devices. Daisy chaining can allow the connected accommodationstimulation devices to work in synch with each other, which canfacilitate studying the accommodative response in both eyes together.

Without intending to be bound by theory, local stimulation of theembodiments described above is not believed to interfere with motorcontrol of the eye by the patient or user. The electrical stimulationdevice stimulates the ciliary muscle with electrodes positionedproximate to the ciliary muscle. By properly positioning the electrodes,the electrical impulse does not travel beyond the ciliary muscle and thesclera, thus stimulating only the ciliary muscle. Since the electricalstimulation devices only stimulate the ciliary muscle in a localized wayand don't stimulate the extraocular muscles, the accommodationstimulation would not produce convergence eye movements. Convergence eyemovement is the phenomenon where the two eyes normally move towards eachother when attempting to focus on a near object. This uncoupling ofaccommodation and convergence provides for an increased ability to focusthe lens without moving the eye as a consequence of the accommodationstimulation.

The accommodation stimulation scleral contact lens 200 disclosed herecan deliver electrostimulation while providing a comfortable and useablemeans to elicit accommodation in a conscious human and to keep thedevice on the eye 250. In this embodiment, the inner ring electrode 218and the outer ring electrode 216 reside only over the sclera 254 of theeye 250 and may therefore be comfortable to wear on the eye 250.

FIG. 3 depicts an accommodation stimulation scleral annulus 300according to an embodiment. The accommodation stimulation scleralannulus 300 is depicted with an annulus body 301 which substantiallyconforms to the shapes and curvatures of the eye (not shown). Theannulus body 301 can be composed of a material such as those used inconjunction with the accommodation stimulation speculum 100 or theaccommodation stimulation scleral contact lens 200, described withreference to FIGS. 1 and 2 respectively.

An opening 310 is formed in the annulus body 320 which circumscribes thecornea of the eye. The annulus body 301 has an anterior surface 304 anda posterior surface 320. The posterior surface 320 rests above or on thesclera of the eye such that an outer ring electrode 316 and an innerring electrode 318 are brought in electrical contact with the sclera. Asabove, the outer ring electrode 316 and the inner ring electrode 318 arepositioned over a region of the sclera which corresponds to the area ofthe underlying ciliary muscle. The annulus body 310 can be of anapproximately equal width, as depicted, and can be sized toappropriately correspond to the eye of the user.

In operation, accommodation of the lens 258 is achieved in the absenceof an external lens, such as the external lens region 202 described withreference to FIGS. 2A and 2B. The external stimulation at specificfrequencies and amplitudes is delivered through the outer ring electrode316 and the inner ring electrode 318 to create contraction of theciliary muscle and subsequent accommodation of the lens in the eye.

Accommodation Devices with Vacuum Suction

In another embodiment, the accommodation stimulation device can be avacuum suction accommodation stimulation speculum or a vacuum suctionaccommodation stimulation scleral contact lens. In the vacuum suctionaccommodation stimulation speculum or scleral contact lens, vacuumsuction is employed to stabilize the speculum or the scleral contactlens on the eye and to improve the contact of the inner and outer ringelectrodes against the sclera. The embodiments below are described withreference to the speculum design but it is understood that the vacuumsuction described here can be incorporated into other disclosed designs,such as the accommodation stimulation scleral contact lens or theaccommodation stimulation scleral annulus.

FIGS. 4A and 4B disclose a vacuum suction accommodation stimulationspeculum 400 according to an embodiment. FIG. 4A depicts a rear view ofthe vacuum suction accommodation stimulation speculum 400 according toan embodiment. The vacuum suction accommodation stimulation speculum 400can have a speculum body 401, an anterior surface (not visible here), aposterior surface 420, and other components as described with referenceto FIGS. 1A-1C. It is understood, that shapes, sizes, compositions andother physical characteristics described with reference to theaccommodation stimulation speculum 100 can be incorporated into thevacuum suction accommodation stimulation speculum 400 without furtherrecitation.

The speculum body 401 is depicted with the posterior surface 420. Theposterior surface 420 can have an outer ring electrode 416 and an innerring electrode 418. The outer ring electrode 416 and the inner ringelectrode 418 can be substantially similar to the outer ring electrode116 and the inner ring electrode 118 described with reference to FIGS.1A-1C. Further, the posterior surface 420 can have a vacuum opening 422formed therein. The vacuum opening 422 can be any form of opening suchas holes/pores, linear grooves, specific shapes or combinations thereof.In this embodiment, the vacuum opening 422 is depicted as a groove. Thevacuum opening 422 can be positioned anywhere on the posterior surface420 such that secure contact between the outer ring electrode 416 andthe inner ring electrode 418 can be established. In one embodiment, thevacuum opening 422 is a channel or groove positioned between the outerring electrode 416 and the inner ring electrode 418. Though the vacuumopening 422 is depicted here as a single opening, the vacuum opening 422can be a plurality of separate openings of various shapes and sizes.

The vacuum opening 422 can be in fluid connection with a vacuum line 424through a vacuum contact 423. The vacuum contact 423 can connect throughthe speculum body 401 to the vacuum opening 422 such that the vacuum canbe created by an exterior source and delivered to the vacuum opening 422in a controlled fashion. The vacuum contact 423 can direct vacuum fromthe exterior source such that the vacuum delivered through the vacuumopening 422 is uniform. The vacuum is then delivered through thespeculum body 401 to the vacuum opening 422.

The vacuum in the vacuum opening 422 can be achieved usingvacuum-creating devices or methods, such as by using a spring-loadedsyringe, a vacuum pump or other suction source connected with a vacuumopening 422 on the speculum body 401. In this embodiment, vacuum isachieved by placing a spring 432 around or in the plunger 430 connectedwith a syringe base 428. The vacuum line 424 is shown as attached fromthe syringe base 428 to the vacuum contact 423 of the speculum body 401.

FIG. 4B depicts the vacuum suction accommodation stimulation speculum400 adapted to contact an eye 450 according to an embodiment. Thedepiction here shows the eye 450 has a cornea 456 formed over a lens458. At the edge of the cornea 456 is the sclera 454, whichcircumscribes the cornea 456. Located under the sclera 454 is theciliary muscle 452. The ciliary muscle 452 is connected to andmanipulates the lens 458 by contraction or extension. Located on top ofthe sclera 454 and circumscribing the cornea 456 is the accommodationstimulation speculum 400. The posterior surface 420 of the accommodationstimulation speculum 400 can be adapted to contact the sclera 454through at least the outer ring electrode 416 and the inner ringelectrode 418. The vacuum opening 422 is depicted as formed between theouter ring electrode 416 and the inner ring electrode 416. The vacuumopening 422 in this embodiment is a channel formed between and alongsidethe inner ring electrode 418 and the outer ring electrode 416 which isapproximately central to the ciliary muscle 452. In one embodiment, theposterior surface 420 of the accommodation stimulation speculum 400rests against the sclera 454 of the eye 450 with the two concentricelectrodes (e.g. the outer ring electrode 416 and the inner ringelectrode 418) resting on the sclera 454 above the location of theciliary muscle 452.

In operation, plunger 430 is depressed into the syringe base 428, shownwith reference to FIG. 4A. The spring 432 applies force to the syringebase 428 in an opposite direction from the force the spring 432 appliesto the plunger 430. Thus, the plunger 432 creates suction in the syringebody 428 which is proportional to the force applied by the spring 432.The suction in the syringe body 428 is translated through the vacuumline 424 to the vacuum opening 422 in the speculum body 401. Asdescribed above, the speculum body 401 has a channel or a groove formedin the posterior surface 420 so that the suction creates a vacuumbetween the posterior surface 420 and the sclera 454, thus pulling andholding the speculum body 401 onto the eye 450. As described withreference to FIG. 1C, external stimulation of specific frequencies andamplitudes can be delivered such that contraction of the ciliary muscle452 and subsequent accommodation of the lens 458 can be achieved.

In the above embodiment, a vacuum suction accommodation stimulationspeculum 400 is disclosed. By forming a vacuum between the sclera 454and the posterior surface 420, the vacuum suction accommodationstimulation speculum 400 can be held in better position and the innerand outer ring electrodes 416, 418 can be brought into more intimatecontact with the sclera 454. By forming a vacuum between the twosurfaces, mobility of the vacuum suction accommodation stimulationspeculum 400 can be decreased and better delivery of electrostimulationto the ciliary muscle 452 can be achieved.

Scleral Stimulation of Accommodative Intraocular Lens

FIG. 5 depicts a accommodation stimulation contact lens 500 adapted tocontact an eye 550 according to an embodiment. The accommodationstimulation contact lens 500 can comprise a external lens 502 and ascleral contact region 504 as described with reference to FIG. 2. Anouter ring electrode 516 and an inner ring electrode 518 can be formedin, on or in connection with the scleral contact region 504. The outerring electrode 516 and the inner ring electrode 518 can have the sameattributes and characteristics as described with reference to the outerring electrode 116 and the inner ring electrode 118 described withreference to FIG. 1A-1C.

The accommodation stimulation contact lens 500 is depicted in contactwith the eye 550. The eye 550 is depicted with a cornea 556, a sclera554 and a ciliary muscle 552, as described above with reference to FIG.1C. The ciliary muscle 552 is connected to and manipulates theaccommodative intraocular lens 558 by contraction or extension. Locatedon top of the sclera 554 and the cornea 556 is the accommodationstimulation contact lens 500.

The external lens 502 can be adapted to contact the cornea 556. Theexternal lens 502 can be simply transparent or it can be corrective,such as for astigmatism, near-sightedness or far-sightedness. Thescleral contact region 504 of the accommodation stimulation scleralcontact lens 500 can be adapted to contact the sclera 554 through atleast the outer ring electrode 516 and the inner ring electrode 518. Inone or more embodiments, the scleral contact region 504 is directly onthe sclera 554. In one embodiment, the posterior surface 520 of theaccommodation stimulation contact lens 500 rests against the sclera 554of the eye 550 with the two concentric electrodes (e.g. the outer ringelectrode 516 and the inner ring electrode 518) resting on the sclera554 above the location of the ciliary muscle 552.

In this embodiment, the natural lens of the eye 550 has been replaced bythe accommodative intraocular lens 558. The accommodative intraocularlens 558 comprises a transparent electroactive polymer. Theaccommodative intraocular lens 558 can incorporate other materials, suchas polymers described with reference to the external lens 502, 302, solong as the accommodative intraocular lens 558 remains responsive to theexternally applied electrostimulation.

As described with reference to FIG. 1C, electrostimulation at specificfrequencies, pulse widths and amplitudes can be delivered such thatcontraction of the ciliary muscle 552 and subsequent accommodation ofthe accommodative intraocular lens 558 can be achieved. In thisembodiment, dual accommodation can be achieved by using the externallens 502 in conjunction with the electrostimulation of the ciliarymuscle 552. The electrical connections and power source used in thisembodiment can be the same as those described with reference to FIG. 3.When an electrical stimulus is received by the ciliary muscle duringelectrostimulation from the power source, the electrical stimulus isalso received by the accommodative intraocular lens 558. The ciliarymuscle 552 contracts and the accommodative intraocular lens 558 moves ina corresponding fashion to produce accommodation. As described above,the electrostimulation in this embodiment can be activated based onphysiological detectors or it can be activated manually, such that thepatient can self-manipulate the dual accommodation response of theaccommodative intraocular lens 558.

Though this embodiment is described with reference to the accommodationstimulation scleral contact lens 500, other embodiments described hereinare expected to provide the same dual accommodation benefit. In oneembodiment, the accommodation stimulation speculum 100 can be used inplace of the accommodation stimulation scleral contact lens 500 toachieve accommodation at the accommodative intraocular lens 558.

In the above described embodiment, the electrostimulation deliveredthrough the accommodation stimulation scleral contact lens 500 isreceived by both the ciliary muscle 552 and the accommodativeintraocular lens 558 to create the accommodative response. Thistechnology can provide numerous benefits, especially for patients that,due to a disease state, have lost use of the natural lens. For example,cataracts cloud the natural lens and presbyopia causes a loss of naturalaccommodation. By the described methods and apparatus, naturalaccommodation and sight or better can be restored.

The accommodative intraocular lens as described herein can be used torestore accommodation to the presbyopic eye. Accommodative intraocularlenses may be implanted in the eye during a non-related procedure, suchas cataract surgery. The implanted accommodative intraocular lens canthen undergo accommodation in response to ciliary muscle contraction. Infurther embodiments, other restorative events which increase theflexibility may be used in combination with the accommodation devicesdescribed above. One restorative event can be a medication that isintended to be administered to the eye and diffuse into the presbyopiclens, where the medication softens the lens to restore accommodation.Another restorative event can be a laser surgical procedure in which oneor more laser cuts are made in the presbyopic lens, such that theoverall stiffness of the lens is reduced, to restore the accommodativeability to the presbyopic lens.

In any of these procedures or any other accommodation restorationprocedures, it may be advantageous to stimulate the ciliary muscleduring the treatment or following the treatment. Electrically stimulatedaccommodation could be used for facilitating the efficacy of thetreatment, such as to facilitate the diffusion of the drug into the lensby using electrically stimulated ciliary muscle contraction toeffectively massage the lens. Electrically stimulated accommodationcould be used after laser cuts are made into the lens to facilitate theeffectiveness of the laser cuts in softening the lens. In anotherembodiment, electrically stimulated accommodation could be usedintraoperatively after a surgeon has introduced an accommodativeintraocular lens into the eye to ensure optimal positioning of theintraocular lens in the eye or to allow the surgeon to observe if theintraocular lens is undergoing accommodative changes in response toelectrically stimulated ciliary muscle contraction.

The accommodation stimulation devices described herein can also be usedfor measuring the electrical activity produced at or received by theciliary muscle. The ciliary muscle generates electrical impulses when itcontracts as part of a voluntary effort to accommodate. The electrodesof the accommodation stimulation devices described above are generallypositioned immediately above the ciliary muscle. As such, it is believedthat the electrodes may be ideally suited to record the ciliary muscleelectrical activity.

Ciliary muscle activity can be recorded when a patient or user makes avoluntary accommodative effort, such as when the patient or userattempts to focus on a near object. Recording ciliary muscle activity isbelieved to be useful in a variety of activity measurement situations,such as for measuring the magnitude of the ciliary muscle contraction,for measuring the magnitude of an accommodative effort a patient or userproduces, for determining if the ciliary muscle is contracting when apatient or user makes an effort to focus or for using the recordedciliary muscle electrical activity as a trigger effect to triggerstimulation from the accommodation stimulation device. In oneembodiment, the ciliary muscle produces an electrical signal in responseto an attempt by the patient or user to accommodate. This electricalsignal is received by the accommodation stimulation device and measuredat either the accommodation stimulation device or a detection device.The received electrical signal can be recorded without furtherinteraction or it can be used as an indicia for a secondary event.Secondary events can include, but are not limited to, the receivedsignal being used to trigger the delivery of external stimulation fromthe accommodation stimulation device. The external stimulation can be ata frequency and amplitude as described above with reference to FIG. 1C.

Further applications of electrical stimulation of accommodation, usingone or more of the embodiments described above, include situations whenaccommodation cannot be stimulated by other means. There may becircumstances where it is not possible to get a patient to elicit avisual stimulus driven or a voluntary elicited accommodative response.Such situations include in a blind eye where the eye cannot perceive anear target or cannot perceive a blurred image. Further examples includean eye with a large depth of focus due to optical aberrations such asastigmatism or spherical aberration, or in eyes that may have degradedvision such as from clouding of the lens such as cataract. In cases suchas this, standard methods for eliciting accommodation in an eye bypresenting the eye with a visual stimulus may not be effective. In theseinstances, electrically stimulated accommodation using the embodimentsdescribed herein may provide a mechanism of determining theaccommodative amplitude or the accommodative potential of the eye.

Further applications of electrically stimulated accommodation include inexperiments on animals. Animals are often used to study accommodationand presbyopia or to do research on accommodation and presbyopia or tostudy accommodation restoration concepts or to study procedures aimed atreversing presbyopia. Electrical stimulation of accommodation in animalmodels can require invasive surgical procedures to expose nerves thatenter the eye or to insert electrodes into the brain centers thatcontrol accommodation. The use of an electrode that is placed on theanimal eye to stimulate accommodation, substantially decreases risk ofinjury to the animal while providing substantially similar results in anon-invasive fashion. This approach also allows accommodation to bestimulated in any animal without any other prior preparatory procedureshaving been performed on the animal.

Examples

FIGS. 6A-6C are graphical depictions of measurements related toaccommodative responses created by an accommodation stimulation deviceaccording to the embodiment described with reference to FIGS. 1A-1C.FIG. 6A shows a graph 600 depicting five individual, dynamicallyrecorded, accommodative responses. The responses were recorded using aninfra-red light-based photorefractor. Infra-red light basedphotorefractors which can be modified for embodiments of this inventioninclude the Accommodation Meter from PlusOptix, Inc., located inNuremberg, Germany. The y-axis depicts the accommodation measured inDiopters (D) and the x-axis is time measured in seconds (s) from anarbitrary start point prior to the beginning of accommodativestimulation.

Each of the five measurements depict a rapid onset of accommodation witha plateau of approximately 8 Diopters. The accommodative response wasstimulated for approximately 4 seconds, with the response plateau beingmaintained for approximately 2.5 seconds. Graph 600 further shows theaccommodative response with low noise, reflecting a controlledaccommodation which is not limited by variability in basal ciliarymuscle tone. Once the electrical stimulation from the accommodationstimulation device was stopped, the eye rapidly returned to the baselinestate. Thus, accommodation is achievable in a rapidly inducible fashionwith limited noise using the accommodation stimulation devices describedabove.

FIG. 6B shows a graph 620 depicting the durations of the electricalpulse-trains, as delivered to the ciliary muscle to achieve theaccommodative response. The electrical impulses depicted were recordedat an intermediate stimulus amplitude of 30% of the maximum possible, asdescribed with reference to FIG. 1C. Graph 620 shows a rapid transitionbetween the delivery of the electrical impulses and cessation of theelectrical impulses. Each of the five electrical pulse-trains lasted forapproximately four seconds with a sharp rise to the desired level ofelectrical input and a sharp fall to baseline.

Thus, FIGS. 6A and 6B together show that accommodation is achievedcontrollably, reversibly and with direct correlation to the electricalstimulation delivered by the accommodation stimulation device. Eachstimulation closely correlates with the measured optical change, oraccommodative response, of the eye. Further, the electrical stimulationsare capable of maintaining the level of accommodation desired for theperiod of time desired, as correlated to the plateau of the impulse.

FIG. 6C shows a graph 640 depicting the velocity of accommodationaccording to an embodiment. The velocities shown in FIG. 6C are thevelocities achieved in the accommodative responses shown in FIG. 6Ausing the electrical stimulation depicted in FIG. 6B. The velocityprofiles are calculated using a two point difference calculation.

Observable in graph 640, the velocity of both the accommodation and therelaxation of accommodation is sharp and definable, when using the abovedescribed accommodation stimulation device. Noise is a common difficultyin accommodative measurement. Accommodation eliciting techniques, suchas visual stimulus elicited accommodation, are generally limited by thestrength and tone of the ciliary muscle. Thus, accommodation stimulatedusing these accommodation stimulation techniques tend to createvariability in the accommodative response resulting in background noiseunrelated to the accommodation event. This background noise iscompounded during subsequent data processing, such as determination ofvelocity, which can make this derivative data either less precise orunusable. The low noise accommodation data, described with reference toFIG. 6A, is therefore particularly amenable to various kinds of analysis(such as the velocity profile calculations) that would not normally bepossible with data which includes more noise, such as accommodation datacollected and studied from voluntary accommodation or with visualstimulus elicited accommodation.

FIGS. 7A-7C depict a plurality of stimulated accommodative responsesusing the accommodation stimulation device described above withreference to FIGS. 6A-6C. FIG. 7A is a graph 700 of elicited andmeasured accommodative responses over an extended period of time. Theaccommodative responses were produced by electrical stimulation, shownwith reference to graph 720 of FIG. 7B. Measurements were performedusing the accommodation stimulation device described with reference toFIGS. 1A-1C and using parameters described with reference to FIGS.6A-6C. Graph 700 shows 20 individual accommodative responses with anaverage maximum amplitude of approximately 7 Diopters which wereelicited by the accommodation stimulation device. The accommodativeresponses were elicited and recorded over a period of 170 seconds.

FIG. 7B shows a graph 720 depicting the durations of the electricalpulse-trains, as delivered to the ciliary muscle to achieve theaccommodative response. The electrical impulses depicted were deliveredat an intermediate stimulus amplitude of 30% of the maximum possible andat a constant frequency and pulse-width, as described with reference toFIG. 1C.

FIG. 7C is a graph 740 depicting the velocities of the accommodativeresponses stimulated by the accommodation stimulation device. Velocitiesshown here were calculated from the accommodative responses describedwith reference to FIG. 7A.

Graph 740 depicts the time of onset and termination of each of the 20responses and the calculated velocity profile of each of the 20individual accommodative responses. The calculated velocity includes thevelocity of both the accommodation event (positive numbers) and therelaxation of accommodation (negative numbers). The velocity ofaccommodation and the velocity of relaxation of accommodation isconsistent and is maintained over the stimulations, as delivered over atime period of 140 seconds.

FIGS. 8A-8D depict a plurality of stimulated accommodative responsesusing the device described above with reference to FIGS. 6A-6C. FIG. 8Ais a graph 800 of elicited and measured accommodative responses over anextended period of time. The accommodative responses were produced byelectrical stimulation, shown with reference to graph 820 of FIG. 8B.Accommodation was stimulated using the accommodation stimulation devicedescribed with reference to FIGS. 1A-1C and using parameters describedwith reference to FIGS. 6A-6C. Graph 800 shows 150 individualaccommodative responses with a maximum amplitude of approximately 7Diopters which were elicited by the accommodation stimulation device.The accommodative responses were elicited and recorded continuously overa period of 20 minutes.

FIG. 8B shows a graph 820 depicting the durations of the electricalpulse-trains, as delivered to the ciliary muscle to achieve theaccommodative response. The electrical impulses depicted were recordedat an intermediate stimulus amplitude of 30% of the maximum possible anda constant frequency of 200 Hz, as described with reference to FIG. 1C.

FIG. 8C is a graph 840 depicting the velocities of the accommodativeresponses stimulated by the accommodation stimulation device. Velocitiesshown here were calculated from the accommodative responses describedwith reference to FIG. 8A as achieved using the accommodationstimulation device described with reference to FIGS. 1A-1C. Thestimulation and relaxation velocities of the accommodative responses canbe consistently measured over an extended period of time.

It is believed that, since this is an intermediate amplitude response,increasing the stimulus amplitude will result in a further increase inthe response amplitude, up to the maximum accommodative response in anindividual. Thus, a stimulus amplitude sufficient to achieve the fullaccommodative response can be used and the accommodative responses wouldsimilarly be sustained for protracted periods and durations ofaccommodation stimulation.

FIG. 8D depicts a graph 860 of the maximum accommodative responseamplitudes of each accommodative response. As stated above, the maximumaccommodative response amplitude observed was approximately 7 Dioptersas measured in 150 stimulated accommodative responses. Shown here, thereis no significant change in magnitude of accommodative responseamplitudes during many repeated accommodation stimulations, even over anextended period of time. As stated above, since these are intermediateaccommodative response amplitudes, using a higher stimulus amplitudewould result in a higher accommodative response amplitude.

FIGS. 9A-9C depict a plurality of stimulated accommodative responsesusing the accommodation stimulation device described above withreference to parameters used in FIGS. 6A-6C. FIG. 9A is a graph 900depicting elicited and measured accommodative responses over an extendedperiod of time. The accommodative responses were produced by electricalstimulation, shown with reference to graph 920 of FIG. 9B. Measurementswere performed using the accommodation stimulation device described withreference to FIGS. 1A-1C and using parameters described with referenceto FIGS. 6A-6C. Graph 900 shows 5 individual accommodative responseswith a maximum amplitude of approximately 8 Diopters which were elicitedby the accommodation stimulation device. The accommodative responseswere elicited and recorded over a period of 80 seconds.

FIG. 9B shows a graph 920 depicting increased stimulus pulse-traindurations compared to the preceding 4-second pulse-train durations inthe preceding graphs, as delivered to the ciliary muscle to achieve theaccommodative response. The stimulus pulse-train durations wereapproximately 10 seconds. The electrical pulse-trains depicted weredelivered at an intermediate stimulus amplitude of 30% of the maximumpossible and a constant frequency of 200 Hz, as described with referenceto FIG. 1C.

FIG. 9C is a graph 940 depicting the velocities of the accommodativeresponses stimulated by the accommodation stimulation device. Velocitiesshown here were calculated from the accommodative responses describedwith reference to FIG. 9A.

FIGS. 10A-10C depict a plurality of stimulated accommodative responsesusing the device described above with reference to parameters used inFIGS. 6A-6C. FIG. 10A is a graph 1000 of elicited and measuredaccommodative responses over an extended period of time. Theaccommodative responses were produced by electrical stimulation, shownwith reference to graph 1020 of FIG. 10B. Measurements were performedusing the accommodation stimulation device described with reference toFIGS. 1A-1C and using parameters described with reference to FIGS.6A-6C. Graph 1000 shows 5 individual accommodative responses with amaximum amplitude of approximately 9 Diopters which were elicited by theaccommodation stimulation device. The accommodative responses wereelicited and recorded over a period of 130 seconds.

FIG. 10B shows a graph 1020 depicting increased stimulus pulse-traindurations, as delivered to the ciliary muscle to achieve theaccommodative response. The stimulus pulse-train durations wereapproximately 20 seconds. The electrical impulses depicted were recordedat an intermediate stimulus amplitude of 30% of the maximum possiblewith a constant frequency of 200 Hz, as described with reference to FIG.1C.

FIG. 10C is a graph 1040 depicting the velocities of the accommodativeresponses stimulated by the accommodation stimulation device. Velocitiesshown here were calculated from the accommodative responses describedwith reference to FIG. 10A.

FIGS. 11A-11C depict a plurality of stimulated accommodative responsesusing the device described above with reference to parameters used inFIGS. 6A-6C. FIG. 11A is a graph 1100 of elicited and measuredaccommodative responses over an extended period of time. Theaccommodative responses were produced by electrical stimulation, shownwith reference to graph 1120 of FIG. 11B. Measurements were performedusing the accommodation stimulation device described with reference toFIGS. 1A-1C and using parameters described with reference to FIGS.6A-6C. Graph 1100 shows 5 individual accommodative responses with amaximum amplitude of approximately 8 Diopters which were elicited by theaccommodation stimulation device. The accommodative responses wereelicited and recorded over a period of 180 seconds.

FIG. 11B shows a graph 1120 depicting increased stimulus pulse-traindurations, as delivered to the ciliary muscle to achieve theaccommodative response. The stimulus pulse-train durations wereapproximately 30 seconds. The electrical impulses depicted were recordedat an intermediate stimulus amplitude of 30% of the maximum possible, asdescribed with reference to FIG. 1C.

FIG. 11C is a graph 1140 depicting the velocities of the accommodativeresponses stimulated by the accommodation stimulation device. Velocitiesshown here were calculated from the accommodative responses describedwith reference to FIG. 11A.

Thus, as depicted in FIGS. 9A-11C, the increased duration of thestimulus pulse-trains show that accommodation can be reliably andrepeatedly achieved over multiple intermediate or long duration stimuluspulse-trains, even with complete relaxation between accommodativestimulations. Further, the accommodation velocities and the relaxationof accommodation velocities remain constant between stimulations,showing that the methods, systems and apparatus described here canreliably achieve accommodation without significant change in thevelocity of the response or the return to baseline.

FIGS. 12A-12C depict a single extended stimulated accommodative responseusing the device described above with reference to FIGS. 6A-6C. FIG. 12Ais a graph 1200 of elicited and measured accommodative responses over anextended period of time. The accommodative response was produced byelectrical stimulation, shown with reference to graph 1220 of FIG. 12B.Measurements were performed using the accommodation stimulation devicedescribed with reference to FIGS. 1A-1C and using parameters describedwith reference to FIGS. 6A-6C. Graph 1200 shows a single accommodativeresponse with a maximum amplitude of approximately 7 Diopters which waselicited by the accommodation stimulation device. The accommodativeresponse was elicited and recorded over a period of 60 seconds.

FIG. 12B shows a graph 1220 depicting increased stimulus pulse-traindurations, as delivered to the ciliary muscle to achieve theaccommodative response. The stimulus pulse-train duration wasapproximately 60 seconds. The electrical stimulus was delivered at anintermediate stimulus amplitude of 30% of the maximum possible and aconstant frequency of 200 Hz, as described with reference to FIG. 1C.

FIG. 12C is a graph 1240 depicting the velocities of the accommodativeresponses stimulated by the accommodation stimulation device. Velocitiesshown here were calculated from the accommodative responses describedwith reference to FIG. 12A. Shown here, the accommodations stimulationdevice can achieve an accommodative response over an extended period oftime without significant change to the maximum accommodative responseand without affecting the return to accommodative response baseline.

During some measurements, it may be beneficial to maintain anaccommodation response for an extended period of time in order for aspecific kind of measurement to be completed. For example, MagneticResonance Imaging (MRI) may take 15 to 20 seconds or greater periods oftime, such as 45 seconds, to capture an image. As shown in FIGS.12A-12C, the embodiments described herein can stimulate and maintain anaccommodative response for these time durations or greater.

FIGS. 13A and 13B depict an overlay of stimulated accommodationresponses with progressively increasing amplitudes, according to anembodiment. FIG. 13A is a graph 1300 showing progressively increasingamplitude of accommodative response in response to an increasingstimulus amplitude as a percent (%) of maximum amplitude, shown in graph1320 of FIG. 13B.

Graph 1300 and graph 1320 show that progressively increasing thestimulus amplitude from 0% to 55% in 12 steps increases the responseamplitude from zero Diopters to the maximum accommodative responseamplitude of about 9 Diopters. Shown in graph 1320, a total of twelvestimulus amplitudes, shown here at 2%, 5%, 10%, 15%, 20%, 25%, 30%, 35%,40%, 45%, 50% and 55% are delivered to the ciliary muscle in the eye.For each stimulus amplitude, shown in FIG. 13B, five stimuluspulse-trains of 4 seconds each are delivered. The accommodative responseamplitude, shown in graph 1300, progressively increases and ultimatelyreaches an asymptote for each of the 5 stimulus pulse-trains. The firstseven amplitudes of the 12 stimulus amplitudes are visible presenting anaccommodative response amplitude of about zero Diopters for the 0% and5% stimulus amplitudes, about 0.5 Diopters for the 10% stimulusamplitude, about 2 Diopters for the 15% stimulus amplitude, about 6Diopters for the 20% stimulus amplitude, about 7 Diopters for the 25%stimulus amplitude, about 8 Diopters for the 30% stimulus amplitude andabout 9 Diopters for the 35% stimulus amplitude. The responses to thehigher stimulus amplitudes still produce the same maximum accommodativeresponses of approximately 9 Diopters. The maximum accommodativeresponse is expected to increase or decrease based on the accommodativecapability of the eye.

FIG. 14A is a graph 1400 depicting a typical stimulus responserelationship for increasing stimulus amplitudes according to anembodiment. The stimulus amplitudes shown in graph 1400 increase from 0%to 55%. As shown in the accommodative response data from FIG. 13A, themaximum accommodative response amplitude for this eye is approximately 9Diopters.

In graph 1400, the maximum response occurs for a stimulus amplitude ofabout 35%. Increasing the stimulus amplitude further results in nofurther increase in response amplitude. Using the accommodationstimulation devices described herein, the maximum accommodative responseamplitude available to any given eye can be determined by progressivelyincreasing the stimulus amplitude until an asymptote is achieved. Inaddition, the stimulus amplitude required to achieve a specificaccommodative response amplitude up to and including the maximalresponse can also be determined. For example, if an accommodativeresponse of 6 Diopters is desired, then a stimulus amplitude of 20%should be used based on the data collected for this subject.

FIG. 14B is a graph 1420 depicting peak velocity as a function ofaccommodative amplitude according to an embodiment. Graph 1420 depictsthe velocity of the accommodative response as derived from theaccommodative response data from FIG. 13A at the stimulus amplitudesdepicted in FIG. 13B. The velocity of the accommodative response isplotted against the maximum accommodative response amplitude for thesame accommodative responses. Graph 1420 shows that as the stimulatedaccommodative amplitude increases, the peak velocity of theaccommodative response increases linearly. As stimulated accommodativeresponse amplitude has been shown to be directly correlated to stimulusamplitude, increasing stimulus amplitude as delivered through theaccommodation stimulation device, described above with reference toFIGS. 1A-1C, leads to an increase in the peak velocity of the stimulatedaccommodative response.

Therefore, the accommodation stimulation device is capable of bothcontrolling the accommodative amplitude and the velocity ofaccommodation in the user. It is envisioned that a stimulus pulse-traindelivered through the accommodation stimulation device could have stepsin the amplitude such that the velocity is controlled independent of themaximum accommodative response achieved. For example, a stimuluspulse-train could begin at a high amplitude which is subsequentlyreduced to a medium amplitude, selected to choose a specific maximumaccommodative response amplitude. One skilled in the art will understandthat there are a plurality of possible combinations which could beperformed based on the disclosures described herein.

FIGS. 15A-15C depict a plurality of stimulated accommodative responseswith progressively decreasing frequencies using the device describedabove with reference to parameters described in FIGS. 6A-6C. FIG. 15A isa graph 1500 of elicited and measured accommodative responses over anextended period of time. The accommodative responses were produced byelectrical stimulation, shown with reference to graph 1520 of FIG. 15B.

Accommodative responses were stimulated using the accommodationstimulation device described with reference to FIGS. 1A-1C and usingparameters described with reference to FIGS. 6A-6C. Graph 1500 shows 16individual accommodative responses with a progressively decreasingaccommodative response amplitude, which were elicited by anaccommodation stimulation device described with reference to FIGS.1A-1C. The accommodative responses were elicited and recorded over aperiod of 230 seconds.

The first accommodation response is approximately 6 Diopters which ismaintained in the first five accommodation responses. Beginning with thesixth accommodation response, the maximum amplitude begins to decrease.The sixth accommodation response has a maximum amplitude ofapproximately 5.5 Diopters. The seventh accommodation response has amaximum amplitude of approximately 5 Diopters. The eighth accommodationresponse has a maximum amplitude of approximately 4.5 Diopters. Theninth accommodation response has a maximum amplitude of approximately 4Diopters. The tenth accommodation response has a maximum amplitude ofapproximately 4 Diopters. The eleventh accommodation response has amaximum amplitude of approximately 2 Diopters. The twelfth throughsixteenth accommodation responses have maximum amplitudes ofapproximately 1 Diopters or less, with a progressive decrease from thetwelfth through the sixteenth.

Embodiments described herein include methods for rapidly determining themaximum accommodative amplitude of the eye. With electrical stimulatedaccommodation, the amplitude of the accommodative response can becontrolled by either adjusting the current amplitude of the stimulus orby adjusting the frequency of the stimulus pulses delivered to the eye.Typically clinical methods for objectively measuring accommodation todetermine the maximum accommodative amplitude of an eye can be verylaborious and can be a very demanding task for the patient which cantake many minutes to perform. Because of the lengthy duration of testingrequired, this can result in fatigue to the patient which therebyresults in a failure of the patient to elicit the maximum accommodativeamplitude. The electrical stimulation of accommodation with aprogressively increasing amplitude of the electrical stimulus or aprogressively increasing frequency of the electrical stimulus pulses canprovide a method for determining the maximum accommodative amplitudeavailable to the eye in a very short period of for example 30 seconds toone minute.

This method of electrically stimulating accommodation includes a methodwhereby the electrical stimulus to the eye could be controlled anddelivered by the same instrument that is used to measure theaccommodative response. When the eye accommodates, there is an opticalchange in the refraction of the eye which is caused by the physical orbiometric movements of the lens inside the eye. Instruments that can beused to measure the optical refractive accommodative response of the eyeinclude instruments such as an autorefractor, an aberrometer or aphotorefractor. Instruments that can measure the biometric accommodativeresponse of the eye include instruments such as Optical CoherenceInterferometers (OCT), Ultrasound Biomicroscopes (UBM), Magneticresonance imaging instruments (MRI). Any instrument that can measure theaccommodative response of the eye is referred to here as an ocularmeasurement instrument. Ocular measurement instruments are generallycontrolled by a microprocessor, such as an external computer or aninternal microcontroller or microprocessor. The same microprocessor andits associated software that is used to operate the ocular measurementinstrument could also be used to control and deliver the electricalstimulus to the eye. This combination of both stimulating accommodationand measuring of the accommodative response of the eye with the sameinstrument allows for a feedback-control loop that would facilitate avery rapid determination of the maximum accommodative response of theeye. The software controlling the ocular measurement instrument couldrapidly run through a sequence of stimulations of increasing stimulusamplitudes or a sequence of increasing stimulus frequencies while theocular measurement instrument also simultaneously measures theaccommodative response of the eye. The stimulation and measurementsequence would continue until the ocular measurement instrument haddetermined that the maximum accommodative response of the eye had beenachieved. In this manner, the process of determining the maximumaccommodative amplitude could be achieved very rapidly, such as withinseconds.

FIG. 15B shows a graph 1520 depicting constant stimulus pulse-traindurations, as delivered to the ciliary muscle to achieve theaccommodative response, with progressively decreasing stimuluspulse-train frequencies. The stimulus pulse-train durations wereapproximately 4 seconds. The stimulated accommodative responses depictedwere stimulated at an intermediate stimulus amplitude of 30% of themaximum possible with a steadily decreasing stimulus frequency. Thestimulus frequency was progressively decreased from the first stimuluspulse-train to the sixteenth stimulus pulse-train. Together, graph 1500and graph 1520 demonstrate that the frequency of the stimuluspulse-train can be used to change the accommodative response amplitude.

FIG. 15C is a graph 1540 depicting the velocities of the accommodativeresponses stimulated by the accommodation stimulation device. Velocitiesshown here were calculated from the accommodative responses describedwith reference to FIG. 15A. As shown here, the stimulation andrelaxation velocities of the accommodative responses decrease as theaccommodative response amplitudes decrease. This decrease in stimulationand relaxation velocities is in accordance with what occurs whendifferent accommodative response amplitudes are achieved by stimulatingthe ciliary muscle using different stimulus amplitudes, but with aconstant pulse-train frequency.

FIG. 15D is a graph 1560 depicting the maximum accommodation amplitudefor stimulus pulse-trains with constant amplitude and variable frequencyas described with reference to FIG. 15A-15C. This graph 1560 shows themaximum amplitude of the accommodative responses as depicted in graph1500 of FIG. 15A. Graph 1560 shows that as stimulus pulse-trainfrequency increases with a constant fixed amplitude stimulus,accommodative response amplitude increases to an asymptote of in thiscase about 5.5 Diopters.

It is believed that an optimal pulse train frequency is required toachieve the maximum accommodative response amplitude. As shown here, thestimulus pulse train frequency of between 200 Hz and 1000 Hz achievedthe maximum accommodative response of this eye. As a certain level ofvariability is expected from one eye to the next, the maximumaccommodative amplitude available to any given eye can be determined byprogressively increasing the stimulus frequency until an asymptote isachieved.

Using the maximum accommodation response amplitude as compared to thestimulus frequency, the stimulus frequency required to achieve aspecific accommodative response up to the maximum accommodative responsecan also be determined. For example, in one embodiment, if anaccommodative response of 2 Diopters is desired, then a stimulusfrequency of 50 Hz should be used.

FIG. 15E is a graph 1580 depicting the maximum accommodation amplitudefrom three sets of measurements for stimulus pulse-trains with constantamplitude and variable frequency as described with reference to FIG.15A-15C. Graph 1580 shows the results from three repeats of increasingstimulus pulse-train frequency (shown here as First, Second and Third)on the same eye. The amplitude was maintained constant as the frequencywas varied as described in FIGS. 15A-15C. Graph 1580 shows that thestimulation accommodation device produces consistent results at avarious stimulus frequencies.

As above, it is envisioned that a stimulus pulse-train delivered throughthe accommodation stimulation device could have steps in the frequencysuch that the velocity is controlled independent of the maximumaccommodative response achieved. For example, a stimulus pulse-traincould begin at a high frequency and a constant amplitude which issubsequently reduced to a medium frequency and a constant amplitude,selected to choose a specific maximum accommodative response amplitude.Frequency and amplitude steps described above could also be used incombination to achieve a variety of accommodative response velocitiesand peak accommodative response amplitudes.

FIG. 16 is a graph 1600 depicting a plurality of accommodation responsesin an eye using the accommodation stimulation device with a variablepulse width for the stimulus pulse-train according to an embodiment. Thepulse width of the stimulus pulse train is the width of the plurality ofpulses which form the stimulus pulse train. For example, a stimuluspulse train of 4 seconds can be composed of a plurality of individualpulses with a pulse width of between 100 μs and 10 ms. The number ofpulses multiplied by the width of each pulse in addition to the spacingbetween pulses is equal to the stimulus pulse train.

The pulse-train pulse-width can be delivered at a variety of widths, asmeasured in millisecond (ms), such as from 0.1 ms to 1.0 ms. Thoughdepicted here with a final pulse width of 1.0 ms, embodiments describedherein are not limited to a pulse width of 1.0 ms. As the pulse width isincreased towards 1 ms, the accommodative amplitude increases to anasymptote. Shown in graph 1600, the asymptote is approximately 4Diopters. In embodiments described herein, pulse widths of about 800microseconds (800 μs) or higher can be used to produce the desiredaccommodative response. Shown in FIGS. 14A, 15D and 16, the stimuluspulse-train amplitude, stimulus pulse-train frequency and stimulus pulsewidth can all be adjusted to regulate the accommodative responseamplitude.

FIG. 17A is a graph 1700 depicting the maximum accommodative responsefor each stimulus amplitude for eyes of varying age stimulated by theaccommodation stimulation device according to an embodiment. Theaccommodation stimulation device used in graph 1700 is the accommodationstimulation speculum described in more detail with reference to FIGS.1A-1C. Graph 1700 shows three stimulus response functions as describedwith reference to FIG. 14A. Graph 1700 depicts the stimulus responsefunctions for three monkeys of differing ages with the youngest at 9.85years old (#50), the intermediate monkey at 16.56 years old (#66) andthe oldest monkey at 24.56 years old (#62). Graph 1700 shows that, withincreasing age, the accommodative response amplitude progressivelydecreases. Monkey #50 shows a maximum accommodative response ofapproximately 9 Diopters which is achieved by a stimulus amplitude ofabout 35% of the maximum amplitude. Monkey #66 shows a maximumaccommodative response of approximately 4.5 Diopters which is achievedby a stimulus amplitude of about 35% of the maximum amplitude. Monkey#62 shows a maximum accommodative response of approximately 2 Diopterswhich is achieved by a stimulus amplitude of about 30% of the maximumamplitude. In each eye, the maximum accommodative response amplitudeattainable for that eye is achieved with the increasing stimulusresponse functions.

FIG. 17B is a graph 1720 depicting the maximum accommodative response ineight monkeys of differing ages achieved using an accommodationstimulation device according to an embodiment. The accommodationstimulation device employed here is the accommodation stimulationspeculum described with reference to FIGS. 1A-1C, which is used inconjunction with the stimulus pulse-train frequencies, amplitudes andpulse widths described with reference to FIGS. 14A, 15D and 16.

Shown in graph 1720, the maximum accommodative response achievable bythe accommodation stimulation device is diminished based on age. Betweenthe ages of about 9 years old and about 15 years old, maximumaccommodative response shown here ranges between 8 and 10 Diopters. Inthese monkeys, the accommodative response peaks at approximately 10Diopters in the approximately 11 year old monkey. A sharp drop inmaximum accommodative response was seen between the approximately 14year old monkey and the approximately 17 year old monkey to about 4Diopters. Between the approximately 17 year old monkey and theapproximately 25 year old monkey the decline in maximum accommodativeresponse was steady from about 4 Diopters to about 2 Diopters. Thusgraph 1720 shows that accommodative response can be achieved reliably invarious age groups, even considering age-related decline inaccommodative response capability.

Fabrication Methods

FIGS. 18 and 19A-19B depict an accommodation stimulation deviceaccording to one or more embodiments and methods of forming the same. Bydetermining the internal and external shape of the eye, the electrodescan be positioned more precisely and with better contact to the eye,such that the stimulation may be delivered more precisely and with moreenergy efficiency.

FIG. 18 depicts a method of fabricating an accommodation device,according to an embodiment. The method 1800 can begin by determining theexternal shape of an external portion of the eye using a first imagingdevice, at element 1802. Determining the external shape can includeusing ocular imaging methods to measure the external shape of the frontof the eye to enable construction of an electrode that provides an idealfit to the eye. Imaging methods which may be employed with one or moreembodiments of the invention include Optical Coherence Tomography (OCT),Ultrasound Biomicroscopy (UBM) or Magnetic Resonance Imaging (MRI). Theabove imaging methods may provide either 2D or 3D images of the eye thatcan be used to define best fit of the electrode to each individual eye,thereby customizing the fit of the electrode to the sclera overlying theciliary muscle.

A device sheet is then formed using the external shape of the eye, thedevice sheet having an exterior wall, a first edge, a second edge and aninterior wall, at element 1804. The device sheet may be formed bycutting, melting, ablating, etching or other techniques. When formed bycutting, the device can be cut on a contact lens lathe. The device sheetcan be formed of standard contact lens materials, such as polymethylmethacrylate (PMMA). In one embodiment, the contact lens lathes receivesa data file from a user that describes the parameters of the surfaces tobe cut. The data file can incorporate both user specification andinformation from the ocular imaging described above. Using this input,one surface can be cut from a button of the desired material. Thisbutton with one cut surface is then detached, turned around, remountedon the lathe and then the second surface is cut. A method forfabricating the electrode may also include cutting concentric grooves inthe inner surface of the electrode using a contact lens lathe to creategrooves into which the electrode conductive wires can be set and gluedinto place.

An internal shape or an internal positioning of an internal portion ofthe eye can then be determined using a second imaging device, at element1806. Some of these imaging methods also allow visualization of theinternal portions of the eye, such as the ciliary muscle. This imagingcan be performed using the same device or technique as the externalimaging or using a separate device or technique. This information can beemployed in the design of electrodes to ensure that the electricalcontacts of the conductive elements of the electrode are optimallypositioned with respect to the location of the ciliary muscle within theeye.

A plurality of concentric grooves can then be formed in the interiorwall, at element 1808. In one embodiment, the imaging of the ciliarymuscle is employed to position the concentric grooves proximate to theciliary muscle of the eye. The electrode can comprise at least anegative (anode) and a positive (cathode) electrode. The electrodes canbe configured into two concentric rings. Each of the anode and cathodecan include a single conductive wire, or each of the anode and cathodecan include a set of conductive wires, each being comprised of two ormore smaller diameter wires. Each of the cathode and the anode caninclude a single sheet of conductive material, such as a wire which isformed in a deposition procedure on a printed circuit board.

The conductive material can then be positioned into the plurality ofconcentric grooves, at element 1810. A method of fabrication of theelectrode can include printing electrodes with conductive material on aflat, but moldable circular or annular shaped plastic material. Theplastic material can be molded with heated or pressurized forces to moldthe material into the shape of a contact lens or an annulus that wouldfit on the eye.

The first edge can then be connected to the second edge to form anaccommodation device, at element 1812. A method of fabrication of theelectrode includes creating an annulus from a flattened sheet ofmaterial with the conductive wires laid down and adhered to theflattened sheet. The edges of the flattened sheet could then be joined,such as by gluing or adhering them together, to form the annulus. In oneembodiment, the conductive material may be protruding through the joinedends of the annulus.

FIGS. 19A and 19B depict an accommodation stimulation scleral annulus1900 fabricated according to an embodiment. FIG. 19A depicts anaccommodation stimulation scleral annulus 1900 cut according to themethod described in FIG. 18. The accommodation stimulation scleralannulus 1900 is shown here as a flat sheet from the view of a posteriorsurface (inner wall) 1920, with an opening 1910, an outer ring 1913, afirst edge 1911 a and a second edge 1911 b. Traces 1922 a and 1922 b areformed in the posterior surface 1920. The traces 1922 a and 1922 b canthen receive the conductive material to form an inner ring electrode1916 and an outer ring electrode 1918. The inner ring electrode 1916 andthe outer ring electrode 1918 have electrode extensions 1914 a and 1914b respectively.

FIG. 19B depicts the accommodation stimulation scleral annulus 1900formed according to the method described in FIG. 18. The accommodationstimulation scleral annulus 1900 is depicted with an annulus body 1901which substantially conforms to the shapes and curvatures of the eye(not shown). The annulus body 1901 can be composed of a material such asthose used in conjunction with the accommodation stimulation speculum100 or the accommodation stimulation scleral contact lens 200, describedwith reference to FIGS. 1 and 2 respectively.

An opening 1910 is formed in the annulus body 1920 which circumscribesthe cornea of the eye. The annulus body 1901 has an anterior surface(outer wall) 1904 and the posterior surface 1920. The posterior surface1920 rests above or on the sclera of the eye such that an outer ringelectrode 1916 and an inner ring electrode 1918 are brought inelectrical contact with the sclera. As above, the outer ring electrode1916 and the inner ring electrode 1918 are positioned over a region ofthe sclera which corresponds to the area of the underlying ciliarymuscle. The annulus body 1910 can be of an approximately equal width, asdepicted, and can be sized to appropriately correspond to the eye of theuser.

The first edge 1911 a and the second edge 1911 b are then joined to forma connection 1912 with holes 1922 a and 1922 b. The electrode extensions1914 a and 1914 b can extend through holes 1922 a and 1922 brespectively. The electrode extensions 1914 a and 1914 b can be used toform the first connection 106 and the second connection 108, as shownwith relation to the accommodation stimulation speculum 100 of FIGS. 1Aand 1B.

In another embodiment, a method of fabrication of the electrode caninclude creating a mold such as an injection mold. The mold can receivea liquid, such as a liquid polymer or silicone, which is poured orinjected into the mold. When the liquid sets or polymerizes, the annulusor lens can be removed from the mold ready to be placed on the eye. Sucha mold could have grooves formed into one surface, which can receive theconductive wires. The wires can be integrated into the mold, such thatwhen the liquid silicone or polymer is set and the set polymer removed,the wire electrodes would be partially embedded in the set polymer orsilicone. A method of fabrication of the electrode can also includemodeling the form of the electrode in 3D computer aided design (CAD)software and then 3D printing the annulus in a biocompatible material.

Radio Frequency (RF) Wireless Control

In its current formulation, the electrode has electrically conductivewires that connect the stimulator that delivers the electrical stimulusto the electrode on the eye. These conductive wires carry the currentfrom the stimulator to the eye. It is possible that the electricalstimulus could be delivered wirelessly with radio frequencies (RF) froman RF transmitter on the stimulator to a RF receiver located on theelectrode. The electrode on the eye would need to have an RF receiver, amicrocontroller and a power source. When the wirelessly transmittedstimulus is received, that signal would be interpreted and then theelectrical stimulus would be delivered from the power source. This wouldallow the patient to wear the electrode more comfortably on the eyewithout the need to have electrically conductive wires to the electrodeon the eye.

FIG. 20 depicts the accommodation stimulation scleral annulus 2000including an RF transmitter 2022 according to one embodiment. Theaccommodation stimulation scleral annulus 2000 is depicted with anannulus body 2001 which substantially conforms to the shapes andcurvatures of the eye (not shown). The annulus body 2001 can be composedof a material such as those used in conjunction with the accommodationstimulation speculum 100 or the accommodation stimulation scleralcontact lens 200, described with reference to FIGS. 1 and 2respectively.

An opening 2010 is formed in the annulus body 2020 which circumscribesthe cornea of the eye. The annulus body 2001 has an anterior surface(outer wall) 2004 and a posterior surface (inner wall) 2020. Theposterior surface 2020 rests above or on the sclera of the eye such thatan outer ring electrode 2016 and an inner ring electrode 2018 arebrought in electrical contact with the sclera. As above, the outer ringelectrode 2016 and the inner ring electrode 2018 are positioned over aregion of the sclera which corresponds to the area of the underlyingciliary muscle. The annulus body 2010 can be of an approximately equalwidth, as depicted, and can be sized to appropriately correspond to theeye of the user.

The accommodation stimulation scleral annulus 2000 further includes anRF transmitter 2022, a microprocessor 2024 and a power supply 2026. Themicroprocessor 2024 receives one or more signals.

For the electrode on the eye that is used to record the accommodativecontraction of the ciliary muscle, normally, this would be accomplishedby connecting electrically conductive material from the accommodationstimulation scleral annulus 2000 on the eye to the preamplifier (notshown). The preamplifier would amplify the recorded muscle potentials inorder to record them. However, using a RF transmitter 2022 on theaccommodation stimulation scleral annulus 2000, the recorded potentialscould be wirelessly transmitted from the accommodation stimulationscleral annulus 2000 on the eye to the preamplifier and recorder. Thiswould allow the ciliary muscle activity that occurs with accommodationto be recorded wirelessly.

Allowing both accommodation stimulation to be delivered wirelessly andaccommodative ciliary muscle contractions to be recorded wirelesslywould mean that the stimulating electrode or the recording electrodecould be more comfortably and more functionally worn on the eye forprolonged periods of time. This would facilitate everyday use of theseaccommodation stimulation devices and allow them to be maintained andused on the eye for daily activities, such as for remotely controllingthe accommodative response of the eye while reading for prolongedperiods of time, or for the remote monitoring of ciliary muscle functionto provide feedback control of an electro-active polymer accommodativeintraocular lens. A patient could wear the stimulation electrode on theeye and with a remote controlled device such as a smart phone or a smarttablet, initiate the delivery of a stimulus to the eye to allow the eyeto change focus by a controlled amount so that the eye could maintainfocus on an object that is at a certain distance from the eye. Thiswould allow the user remote control or automated control of theaccommodative response using RF wireless electrical stimulation. Thesmart phone in this instance could detect the distance of the device tothe eye and deliver a stimulus of the appropriate magnitude to allow theeye to focus appropriately on the smartphone.

Pre-Operative Screening of Patients for Accommodative Function

The embodiments, as described above, can be used both in accommodationand detection of accommodation or attempted accommodation. Older patientpopulations, such as patients over the age of 50, may providedifficulties not seen in other patient populations, because some of themmay not have experienced accommodation for some years. As such,conventional testing for accommodation in this group of patients ischallenging.

It is believed that presbyopia results from an age-related stiffening ofthe presbyopic lens in the eye and that the ciliary muscle remainsfunctional throughout life, including beyond the age at whichaccommodation is completely lost. However, since older presbyopicpatients may not have been able to focus at near for some years, it ispossible that some patients may have either lost strength in theirciliary muscle or that some patients may have completely lost theability to elicit an accommodative response in the ciliary muscle. It ispossible, therefore, that some patients may not be suitable candidatesfor accommodation restoration procedures because of their inability toproduce accommodative contractions of the ciliary muscle.

Using the above embodiments, patients may be screened pre-operatively orbefore presbyopia treatments commence to determine if they are suitablecandidates for accommodation restoration procedures. This screening cansave considerable expense and could improve patient outcomespost-operatively, by ensuring that only suitable candidates are selectedfor the accommodation restoration procedures.

Pre-operative electrical stimulation of accommodation or recording ofelectrical potentials from the ciliary muscle when patients make aneffort to accommodate offers an opportunity to evaluate which patientsmay or may not be most suitable for accommodation restorationprocedures. If strong electrical potentials can be recorded from theciliary muscle pre-operatively in patients while they make anaccommodative effort, this would provide evidence that the ciliarymuscle is undergoing a strong contraction. If electrical stimulation ofthe ciliary muscle shows significant movements of the lens in the eye,such as a downward sag of the lens under the influence of gravity withan accommodative contraction of the ciliary muscle, this may indicatethat the ciliary muscle is undergoing a strong contraction. Patientswith strong ciliary muscle contractions would be ideal candidates foraccommodation restoration procedures, while patients that show noaccommodative contraction of the ciliary muscle would be poorcandidates.

While the foregoing is directed to embodiments of the inventions, otherand further embodiments of the inventions may be devised withoutdeparting from the basic scope thereof.

1. An electrostimulation device, comprising: a device body with acircular shape and an outer circumference, the device body comprising aposterior surface and an anterior surface, the posterior surface beingshaped to fit an eye; an inner ring electrode comprising anelectrically-conductive material and formed on the posterior surface; anouter ring electrode comprising an electrically-conductive material andformed on the posterior surface; and an electrical stimulation source inelectrical connection with the inner ring electrode and the outer ringelectrode.
 2. The electrostimulation device of claim 1, wherein theelectrically-conductive material comprises a biocompatible conductivematerial.
 3. The electrostimulation device of claim 1, wherein thedevice body is composed of a non-conductive material.
 4. Theelectrostimulation device of claim 1, wherein the outer ring electrode,the inner ring electrode and the outer circumference of the device bodyform concentric circles.
 5. The electrostimulation device of claim 1,wherein the outer ring electrode and the inner ring electrode arepositioned on the sclera such that the outer ring electrode is formedaround an outer boundary of a ciliary muscle and the inner ringelectrode is formed around an inner boundary of the ciliary muscle. 6.The electrostimulation device of claim 1, wherein the electricalstimulation source comprises a battery formed on or in the device body.7. The electrostimulation device of claim 1, further comprising awireless connection for communication between the electrostimulationdevice and a computing device.
 8. The electrostimulation device of claim1, further comprising an intraocular lens.
 9. The electrostimulationdevice of claim 1, wherein the position of the inner ring electrode andthe outer ring electrode with relation to a ciliary muscle of the eye isdetermined using intraocular imaging, such that the inner ring electrodeis positioned over the outer boundary of the ciliary muscle and theouter ring electrode is positioned over an outer boundary of the ciliarymuscle.
 10. An accommodation stimulation device comprising: a devicebody comprising: a transparent lens with a posterior surface and ananterior surface, the posterior surface adapted to contact the cornea;and a scleral contact region with a posterior surface and an anteriorsurface, the scleral contact region circumscribing the transparent lens;an inner ring electrode comprising an electrically-conductive materialadapted to contact the posterior surface of the scleral contact region;an outer ring electrode comprising an electrically conductive materialadapted to contact the posterior surface of the scleral contact regionand circumscribing the inner ring electrode; and a power source inelectrical connection with the inner ring electrode and the outer ringelectrode.
 11. The accommodation stimulation device of claim 10, whereinthe electrically-conductive material is composed of a biocompatibleconductive material.
 12. The accommodation stimulation device of claim10, wherein scleral contact region is composed of a non-conductivematerial.
 13. The accommodation stimulation device of claim 10, whereinthe outer ring electrode, the inner ring electrode and the outercircumference of the device body forming concentric circles
 14. Theaccommodation stimulation device of claim 10, wherein the outer ringelectrode and the inner ring electrode are composed of a plurality ofrings.
 15. The accommodation stimulation device of claim 10, wherein theelectrical stimulation source comprises a battery formed on or in thedevice body.
 16. The accommodation stimulation device of claim 10,further comprising a wireless connection for communication between theelectrostimulation device and a computing device.
 17. The accommodationstimulation device of claim 10, further comprising an intraocular lens.18. The accommodation stimulation device of claim 10, wherein thetransparent lens is a corrective lens.
 19. An accommodation measurementdevice comprising: a device body with a circular shape and an outercircumference, the device body comprising a posterior surface and ananterior surface; an inner ring electrode comprising anelectrically-conductive material and formed on the posterior surface; anouter ring electrode comprising an electrically-conductive material andformed on the posterior surface, the outer ring electrode, the innerring electrode and the outer circumference of the device body formingconcentric circles; and an electrical measurement device in electricalconnection with either the inner ring electrode, the outer ringelectrode or combinations thereof.
 20. The accommodation measurementdevice of claim 19, further comprising a recording device connected tothe electrical measurement device, such that the recording device canreceive one or more signals or one or more converted signals from theelectrical measurement device which correspond to an accommodationevent.